The present invention relates generally to lift assemblies for implement frames and, more specifically, to a lift wheel arm tower bearing assembly.
Multi-section frames for agricultural implements such as field cultivators or similar soil working implements typically include a main frame and wing sections hinged to opposite sides of the main frame. Wheel assemblies including a wheel arm pivotally connected to frame-mounted axle support the frame sections and provide lift functions for moving the implement between a raised transport position and a lowered field-working position. The wheel assemblies can also function to provide adjustable depth control for the soil-engaging tools on the frame.
In some wheel assemblies, particularly those that support the wing sections, a cylinder anchor tower is pivotally connected to the wheel arm axle for pivoting about the same axis as the wheel arm. The upper end of the tower is connected to one end of an adjustable length linkage, and the opposite end of the linkage is connected to the frame to secure the tower at the desired angle. A cylinder is connected between the wheel arm and the tower. By adjusting the length of the linkage, the wheel assembly position relative to the frame can be changed for leveling frame.
Most previously available wheel arm support and tower assemblies are fairly complex and utilize numerous components. Frictional contact resulting from relative rotation between the tower and the wheel axle each time the wheel arm is moved to raise or lower the implement results in considerable wear. The tower requires expensive welded pivot collars or a casting with a pivot which makes the component heavy and difficult to install and to disassemble. Present support and tower construction is heavy, and convenient positioning of the wheel assembly to a location best optimizing the earthworking tool pattern often is not possible.
It is therefore an object of the invention to provide an improved tower and wheel arm assembly for an implement. It is another object to provide such an assembly which overcomes most or all of the aforementioned problems.
It is also another object of the present invention to provide an improved tower and wheel arm assembly which is simpler and less expensive than at least most previously available assemblies. It is a further object to provide such an assembly having fewer components than most assemblies.
It is yet another object of the present invention to provide an improved tower and wheel arm assembly having an improved bearing arrangement. It is another object to provide such an assembly wherein the tower does not require special bearings or pivot collars and is less subject to wear than at least most previously available towers. It is a further object to provide an assembly wherein lubricated tower bearings are obviated.
A tower and wheel arm assembly includes a pair of single piece pivot castings which are selectively connectable at different locations along the frame and provide both wheel arm pivoting and cylinder anchor tower pivoting. The wheel arm axle extends between the castings and pivots within cylindrical cavities located in the castings. External cylindrical surfaces concentric with the cavities rotatably support a pair of tower plates which include circular openings received over the external cylindrical surfaces.
The dual pivoting function of the one-piece castings provides a simple and relatively inexpensive support arrangement for the wheel arm and tower and eliminates frictional wear between the tower and the axle which otherwise normally occurs when the wheel arm is pivoted to raise and lower the implement. Tower bearing lubrication is not required. Symmetrical casting configuration allows use of the same part for either the right-hand or left-hand support. Simple plate towers which are light in weight may be utilized. A compact, sturdy bearing structure is provided that is easy to connect at various locations along the frame. Assembly and disassembly of the structure is relatively fast and easy. Compared to at least most previously available support and tower constructions, the present assembly is generally lighter and provides more convenient positioning of the assembly for optimizing the tool pattern.